Scavenging muffler for automotive engines



Feb. 7, 19280 MSSAQZ N. WARTH SCAVENGING MUFFLER FOR AUTOMOTIVE ENGINESFiled Oct. 11, 1923 NATHANIELQWARTH 1 =1 Gad/ i a Patented Feb. 7, 1928.

NATHANIEL G. WABTE, F GALLIPOLIS, OHIO. SCAYENGING MUFFLER FOBAUTOMOTIVE ENGINES.

Application filed October 11, 1923. Serial No. 668,019.

The object of this invention is to provide an improved construction ofmufiler for an automobile engine equipped with a manifold and exhaustpipe whereby there is secured in addition to an efficient mufiiingeffect a more etlicient scavenging of the exhaust system andconsequently a reduction of back pressure, and carbon deposit, theseresults efiicient and satisfactory operation of the engine. itself.Because of the effect stated much of the fuel and upkeep expense issaved.

In my construction I utilize suction or entrainment efiects upon thedischarge gas impulses in three cooperating Ways, to wit; first thesuction tending to be created in an injector or siphon nozzle producedby a high velocity current of air collected by a funnel at the head of,themuflier. second the suction created in an injector siphon nozzleproduced by a high velocity turbine driven by the exhaust impulses. thesuction being due to a vacuum effect produced in 5 the exhaust system bythe rotation of the turbine during .the intervals between the gasimpulses and thirdly by the suction tending to be created in an injectoror siphon nozzle arranged about the gas and air nozzle mentioned toentrain the gasesas in the other instances; this last entrainment effectbeing accomplished by directed gases within the muflier passing throughthe injector noz-' zle at high velocity and momentum. These threesuctions are cooperating and coincident in the withdrawal ofthe wastegases from the exhaust system.

The invention is embodied in the example herein shown and described andthe method of operation involved. the features of novelty being finallyclaimed.

In the accompanying drawing Figure 1 is mainly a longitudinal sectionalview of a mufiier according to my present invention.

Fig. 2 is a cross section on the line 11-11 Fig. 1 looking to the right.

Fig. 3'is an end elevation of nel.

Fig. 4 is a similar view illustrating a modification of Fig. 1consisting of a special extension of the main muflier. I

Referring first to Figs. 1-3 the character 5 designates a cylindricalcasing having a forward head 6 and rear head 7 held in the ends of-thecasing by suitable bolts such as the air funtending to promote the moreshown at 8. Supported by suitable spacers 2 within the casing 5 is acylinder 10 having its rear end tapered or contracted rearwardly toreduce its opening as seen at 10 and its forward end rovided with aninternal funnel 11 extendlng rearwardly in the c linder 10 where it issupported in. a spider casting30. The spider 30 is held in position bysuitable posts 31 secured between the outer. casing 5 and" the cylinder10. Said spider 30 can as shown form a prolon ation of the rear end ofthefunnel 11 an constitutes a nozzle. Extending rearwardly into. saidfunnel 11 is a tubular conductor 12 connected at its forward end to therear side of the forward head 6; and communicatin with conductor 12 isan air collecting funne 13 provided with a series of concentric rings 13supported by cross bars 13 for the purpose of directing the atmosphericair against the inclined-inner sides of the funnel and thereforeconcentrate the flow and pressure of the collected air toward andthrough 'the smaller end of the funnel. Within the conductor 12 is atube having a cylindrical portion 14 and a squared rear end at 14: theouter side of said tube and the inner sideof the conductor 12 beingprovided with a series of rings 15 and 16 respectively in staggeredarrangement and rearwardly inclined so as to form a series of circularpockets thereby adapting them to freely admit air from the funnel but toretard with considerable effect any forward flow of gases. Thisretarding arrangement of parts have a sound deadening eifect. Thecharacter 17 designates theexhaust pipe of the engine, said pipe beingcoupled at its discharge end with the forward end of the tube 14. Therear of the tube 14 is a nozzle and is supported on ing 30.

The rear end of the conductor 12 is also a nozzle and is supported bythe spider 30. Said end is tapered and squared at 12" parallel with thesquared end 14 of tube 14: and hinged to each of the four inner sides ofthe end 12 as indicated at 18 is a valve 19 lined at its inner side withasbestos cloth adapted to close at its free end upon the adjacentsquared faces of the squared end 14 of the tube 14. These valve parts 19constitute virtually one valve and each of the parts is provided with astop or projection at its back to contact with the wall 12 of theconductor so as to cause its free end a lip 30 of the cast- V vent maybe regulated.

to be slightly separated from wall 12* when in fully opened position andtherefore permit forward pressures within the muflier to act on theirrear sides to close them.

Secured to the center of the spider 30 is a stationary shaft 21 on therear of which beyond the nozzle of the funnel 11 is jour-' naled withsuitable antifriction bearings a bladed wheel or turbine 22 adapted tobe rotated by the force of the exhaust into the mufiler. Notwithstandingthat the impulses of the exhaust are intermittent their action on theturbine is to keep that member in continuous high speed rotation.

The rear head 7 is provided with a nipple 23 to which is connected apipe extension 24 having its rear end split and flattened, said splitends. being provided with suitable means, as for example, a bolt andnutwhereby the extent of the separation of said ends and consequently thesize of the The heads 6 and 7 are each formed to present internally ofthe mufiier a circularly concaved surface adapted to direct the flow ofgases against themthe curved surface in the head 7 being designed todirect the gases issuing from the opening to the cylinder end 10 intothe annular space between the outer casing 5 and the cylinder 10 whilethe curved surface of the head 6 is designed to convergently direct thegases from the forward end of said annular space into the mouth of thefunnel 11 whence they pass between the inner side of the funnel andtheexterior of conductor 12.

Referring now to Fig. 4 the construct-ion is the same as in Fig. 1except that instead of employing the head 7 as shown in Fig. 1 themulfler casing 5 is lengthened as at 5 to form an extended or additionalchamber in which is located at its'rear end a head 7 containing thedischarge nipple a secondary directing cylinder 10 duly supported andspaced by spacers 9 from the outer casing and a cooperating deflectorend 6 in the forward portion of the extended chamber. In thismodification the secondary or extended chamber is connected with theprimary or main chamber by means of central passage or pipe 33 and inthe primary or main chamber is the curved deflector ring or surface 7corresponding in function to the deflecting head 7 in Fig. 1. In thisconstruction portions of the impelled gases issuing from the contractedopening 10 pass through pipe 33 and are circulated by the head 7 throughthe annular space between the extensions 5 and the secondary cylin-- der10.

It being remembered that the engine exhausts in nnpulses and it beingassumed that the car is in forward motion with air entering the funnelunder pressure the operations are as follows: from the collector funnelthe curs, of course, between the impulses of the' exhaust. During animpulse the gas pres sure bemg greater than the air pressure,

such impulse entrains and augments the intake of air at this point. Theimpulses of theexhaust drive the turbine at a high velocity and duringthe interval between the impulses a vacuum effect is produced for wardof the same at the nozzles, said effect being to suck the gases and airfrom the three nozzles thereby effecting entrainment of the gases fromthe pipe 14, air from the sound deadener. and the mixed gases throughthe funnel 11. The operation for the third scavenging entrainment of thewaste gases consists in a controlled current flow of the gases withinthe mufller to act upon them-- selves. The exhaust impulses of asejected from the exhaust pipe flow direct y through the center of" themufller to the rear head by which they are largely deflected or divergedradially to the casing wall and are driven forwardly between casing 5and cylinder 10 to: the front head, by which head they are deflected,converged and impelled rearwardly into the internal funnel 11 from whichthey are given added velocity and momen tum through the annular nozzleof the funnel by their entrainment, because of the siphon-ejector actionat this nozzle due to the succeeding impulse of gas from the exhaustpipe. The momentumof the flowing gust; continues during the succeedingintermissionor absence of exhaust, and this result 'in turn, causesentrainment of the retained gases in the exhaust pipe-this effectcoutinuing during the operation of the engin whether the car is inmotion or not by reasm of their momentum and the provision to theirbeing returned to the nozzles and re gardless of the continued dischargeof flu largely spent or inactive gases to the atmos-- phere through theexhaust pipe or nipple of the muffler. It'will be understood, of coursethat there always exists some internal pressure of the gases within themuffler while that portion of the gases having the high velocitymovements are following their courses and performing their function, thepressure stated continues to act to effect to discharge the mixture atthe rear exhaust in proportion to the intake or supply at the head.- Inengines having a simultaneous discharge from more numerous cylinders 21larger expansion area or capacity within the mufiier may be desirableand the modification shown in 4 illustrates how the increased capacitymay be provided for. The extended casing provides for a secondarycontrolled flow of the gases thus augmenting the result. The directionsof the gas antenna ward motion the exhaust gases are prevented fromescaping forward by the closing of the valve due to. internal pressureset up under these circumstances, and any noise incident to the forwardescape of gases is prevented by the sound deadener in the conductor 12.

The forms of the parts can be changed without departing from the gist ofthe invcntion as claimed.

What I claim is:

1. In combination with a mer chamber for explosive engines, an aircollecting tunnel-provided at its interior with a seriesofconcentrically located rings spaced from one another and at theirinner ends spaced from the wall of the tunnel, said rings being or fincreasing length from the outermost to theinnermost of the series andadapted to direct air to the sides of the funnel. v

2. In combination with a mufier chamber for an explosive engine, anexhaust gas conductor therein,.an air collecting funnel having itsdischarge end extending around said exhaust conductor, and sounddeadening members, between said exhaust conductor and said extension ofthe funnel consist of rings on said conductor and extension extendingtowards each other. I

3. In combination with a mufler chamber for an explosive engine, anexhaust gas conductor therein, an air collecting funnel having anextension lying around the exhaust conductor and forming a passagearound the latter, sound deadening members in'said passage, means withinthe chamber for causing the return of exhaust gas to the exterior ofsaid extension, and a valve at the rear end of said passage adapted toclose said passage against the return of gases through said passa c.

l. In combination with a mufiler casing for an explosive engine, anexhaust conduc tor therein, means for supplying air near the dischargeof said exhaust conductor, means within said casing for causing gasesdischarged into the casing to return to points around the air conductorincluding a turbine actuated by the exhaust discharges, a circularconcaved head and a wallforming an annular chamber around the inner sideor the mufiler.

5. In combination with a mufiler casing for an explosion engine, anexhaust conductor therein, means within the casing, for causing gasesdischarged into the casing to return to the region of the discharge ofthe exhaust conductor consisting of acircularly concaved headand a wall,means for directing the returned gases in the direction of the exhaustdischarge, and a turbine between said exhaust conductor and concavedhead actuated by said discharges.

6. In combination with a mufiler casi for an explosion engine, anexhaust conductor therein, means for supplying air near the. dischargeof said exhaust conductor, and means for causing the discharge gases toreturn to points around the air dischar including a turbine actuated bythe exhaust discharges.

7. In combination with a mufller casing for an explosion engine, anexhaust conductor therein, means within the caslng for returning gasesdischarged into the \casing to .the region of the exhaust conductor,means i for directing the returned gases in the direction of the exhaustdischarge, a turbine actuated by the discharges, an air collecting unnelhaving a conductor around said exhaust conductor and a check valve forpre venting return pressure through the space between the air conductorand exhaust con ductor. 1

8. In combination with a mufiler casing for an'explosion engine, anexhaust conductor therein, means within the casing for Feturning gasesdischarged into the casing to the region for directing the returnedgasesin the direction of the exhaust actuated by the discharges, anaircollecting funnel having a conductor around said exhaustconductor and acheck valve for preventing return pressure through the space between theair conductor and exhaust con- 'ductor and sound deadening members instaid space.

9. In a'mufier, an outer casing, a scavenging element therein includingcircularly concaved forward and rear heads in the opposite ends of thecasing facing each other at their concaved sides, the cavityof each ofsaidheads extending from substantially the inner surface of the casingtoward the axis of the casing and said rear head provided with a gasdischarge, an imperfor'ate cylinder mounted within said casing betweensaid heads and spaced from the casing and heads, a gas exhaust conductordischarging through the forward head and into the imperforate rcylinderbeyond the forward end'of the latter; part of the gases discharged fromsaid conductor into said imperforate cylinder being first directedagainst the rear head and then forward between the casingand imperforatecylinder to the exterior of the exhaust conductor and rearwardlythereon.

oi the exhaust conductor, means discharge, a turbine

